I think competing on service quality is only possible where either consumers will accept a price differential or you can manage to avoid any kind of price diffe

I think competing on service quality is only possible where either consumers will accept a price differential or you can manage to avoid any kind of price differential. If I'm at a self-service gas station using the self-service pump and paying at the self-service machine, I really don't care if there's good service from the person behind the counter inside. I certainly wouldn't want to pay more for better service from a person I don't ever interact with.